Bio-inspired 3D porous carbon nanosheets composite materials for high-performance lithium-ion batteries

A bio-inspired strategy has been proposed to synthesize a unique kind of 3D porous cobalt oxide and carbon nanosheet composite materials (PCN@Co₃O₄), as a lithium-ion battery anode material. In this work, turnip has been chosen as a two-dimensional nanobiomass carbon substrate and choosing cobalt salt as the metal precursor by using plant cell suction phenomenon of dehydration to prepare PCN@Co₃O₄. When PCN@Co₃O₄ is applied for the anode material for lithium-ion batteries, it delivers ultrahigh reversible capacity and excellent electrochemical performance. After 100 cycles, PCN@Co₃O₄ has a reversible specific capacity of 1004.2 mA h g⁻¹ at a current density of 100 mA g⁻¹ and a reversible capacity of about 923.7 mA h g⁻¹ after 400 cycles even at a high current density of 1000 mA g⁻¹. Furthermore, it also exhibits a high rate capability, which can be stabilized at about 1151, 939.7, 771.4, and 631.5 mA h g⁻¹ for every 10 successive cycles when increasing the current density to 100, 500, 1000, and 1500 mA g⁻¹, respectively. And a satisfactory-specific capacity can be recovered to the original value (about 1150 mA h g⁻¹) at a current density of 100 mA g⁻¹ after 60 discharge/charge cycles.